<!DOCTYPE html>
<html>
<head>
    <title>输入要查询的序列号</title>
    <style>
        .select {
            top: 0;
            width: 100%;
            background-color: #F8F9FA;
        }

        .content {
            top: 50px;
            overflow: hidden;
            width: 100%;
            height: 100vh;
        }

        iframe {
            overflow: hidden;
            width: 100%;
            height: 100%;
            border: 0;
        }

    </style>
</head>

<body>
    <div class="select">
        <form action="selectsn2.php" method="post" target="dd3">
            <label for="search_term">请输入要查询的设备序列号:</label>
            <input type="text" id="search_term" name="search_term">
            <button type="submit">确定</button>
        </form>
    </div>
    <div class="content">
        <iframe class="content-3" name="dd3"></iframe
    </div>
</body>
</html>